Appearance inspection apparatus

ABSTRACT

An appearance inspection apparatus analyzes a difference in detection characteristics of detection signals obtained by detectors to flexibly meet various inspection purposes without changing a circuit or software. The apparatus includes a signal synthesizing section that synthesizes detection signals from the detectors in accordance with a set condition. An input operating section sets a synthesizing condition of the detection signal by the signal synthesizing section, and an information display section displays a synthesizing map structured based on a synthesized signal which is synthesized by the signal synthesizing section in accordance with a condition set by the input operating section.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuing application of U.S. application Ser.No. 12/482,479, filed Jun. 11, 2009, which is a continuing applicationof U.S. application Ser. No. 11/830,320, filed Jul. 30, 2007, whichclaims priority under 35 U.S.C. §119 to Japanese Patent Application No.2006-207780, filed Jul. 31, 2006, the entire disclosure of which areherein expressly incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an appearance inspection apparatus fordetecting minute foreign matters or defects on a semiconductor wafer.

2. Description of the Related Art

There is a technique in which in an appearance inspection apparatus forinspecting a defect on a surface of a wafer, COP (Crystal OriginatedParticles) defects are discriminated using a scattered light detectingsection (which will appropriately be described as a multi-sensor,hereinafter) having a plurality of detectors disposed around anillumination light spot on a sample such that orientations and elevationangles thereof are different from each other, and utilizing a differencein detection characteristics caused by a difference of an elevationangle of the detectors (see Japanese Patent Application Laid-open No.9-304289 and the like).

SUMMARY OF THE INVENTION

According to the technique disclosed in Japanese Patent ApplicationLaid-open No. 9-304289, detection signals from each detectors of themulti-sensor are synthesized in accordance with software which ispreviously stored so as to discriminate the COP defects, and anobservation image of a wafer in which mainly COP defects are reflectedon a wafer map is structured based on the synthesized signal. However,when it is desired to obtain an observation image of defects havingdifferent detection characteristics other than COP defects such asforeign matters adhered on the wafer surface and flaws on the wafersurface, it is necessary to recompose a signal processing circuit of adetection signal from each detector and to re-structure the software.

To that end, there is required a series of operations such as a: aresult of detection of the multi-sensor is compared with an inspectiondefect of the same wafer by another inspection apparatus and they areanalyzed off-line, b: software suitable for discriminating a newinspection subject (flaw on a wafer surface for example) is preparedbased on the analysis result, and c: the prepared software is installedin the original appearance inspection apparatus. With this, much laborand much time are required in some cases.

It is an object of the present invention to provide an appearanceinspection apparatus capable of analyzing a difference in detectioncharacteristics of detection signals obtained by a plurality ofdetectors, and capable of flexibly meeting various inspection purposeswithout changing a circuit or software.

To achieve the above object, a first aspect of the present inventionprovides an appearance inspection apparatus including a sample stage forsupporting a sample, an illumination light source for irradiating thesample on the sample stage with illumination light, a plurality ofdetectors which are disposed at different positions from each other withrespect to an illumination light spot of the illumination light source,and which detect scattered light generated from a surface of the samplewhen illumination light is emitted from the illumination light source, asignal synthesizing section which synthesizes detection signals from theplurality of detectors in accordance with a set condition, a conditionsetting section for setting a synthesizing condition of the detectionsignal by the signal synthesizing section, and a display section fordisplaying a synthesized sample image structured based on a synthesizedsignal which is synthesized by the signal synthesizing section inaccordance with a condition set by the condition setting section.

According to a second aspect, in the first aspect, the display sectiondisplays a plurality of individual sample images structured based ondetection signals from the plurality of detectors.

According to a third aspect, in the second aspect, the plurality ofindividual sample images are displayed on the same screen as that of thesynthesized sample image.

According to a fourth aspect, in the first aspect, when a setting of thesynthesizing condition of the detection signal is changed by thecondition setting section, the synthesized sample image is newlystructured in accordance with the changed synthesizing condition, andthe change in the synthesizing condition is reflected.

According to a fifth aspect, in the first aspect, the display sectiondisplays a list of detection data by the plurality of detectors.

According to a sixth aspect, in the first aspect, the synthesizingcondition of the detection signals of the plurality of detectors can beset by a GUI operation on a display screen of the display section.

According to the present invention, it is possible to analyze adifference in detection characteristics of detection signals obtained bya plurality of detectors on the apparatus, and capable of flexiblymeeting various inspection purposes without changing a circuit orsoftware.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptional diagram of an appearance inspection apparatusaccording to an embodiment of the present invention;

FIG. 2 is a diagram showing one example of a synthesizing condition of adetection signal;

FIG. 3 is a diagram showing one example of the synthesizing condition ofthe detection signal;

FIG. 4 is a diagram showing one example of the synthesizing condition ofthe detection signal;

FIG. 5 is a diagram showing one example of an analysis screen displayedon an information display section;

FIG. 6 is a diagram showing one example of a simulation screen displayedon the information display section;

FIG. 7 is a diagram showing one example of a data list display screendisplayed on the information display section; and

FIG. 8 is a flowchart showing setting procedure of a synthesizingcondition of a detection signal using the appearance inspectionapparatus according to the one embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be explained using thedrawings below. FIG. 1 is a conceptional diagram of an appearanceinspection apparatus according to the embodiment of the invention. Asshown in FIG. 1, the appearance inspection apparatus includes a samplestage 101, a stage driving section 102, an illumination light source103, a scattered light detecting section 104, a signal synthesizingsection 105, a general control section 106, a mechanical control section107, an information display section 108, an input operating section 109,a storing section 110 and the like.

The sample stage 101 supports a sample 100 of a wafer or the like placedon the sample stage 101. The stage driving section 102 drives the samplestage 101 such that a fixed point (spot) is irradiated with illuminationlight 111 from the illumination light source 103 and the illuminationlight 111 scans on the sample 100.

The stage driving section 102 includes a rotation driving section 115which rotates the sample stage 101 around a rotation shaft 114, and aslide driving section 116 which moves the sample stage 101 in the radialdirection.

When the sample 100 on the sample stage 101 is irradiated with theillumination light 111 by the illumination light source 103, therotation driving section 115 rotates the sample stage 101 and the slidedriving section 116 moves the sample stage 101 in the radial directionso that the illumination light 111 spirally scans on the sample 100relatively.

The scattered light detecting section 104 includes a plurality ofdetectors 120 a to 120 d having different positions with respect to thespot of the illumination light 111. In FIG. 1, four detectors are shownin total, i.e., the detectors 120 a and 120 b disposed at the low anglepositions and the detectors 120 c and 120 d disposed at the high anglepositions, but the number of detectors is not limited only if two ormore detectors are disposed such that at least one of the azimuth anglefrom the illumination light spot and the elevation angle is different.The detectors 120 a to 120 d detect the scattered light 112 generatedfrom the surface of the sample 100 when the illumination light 111 isemitted from the illumination light source 103. A detection signal(which will appropriately be described as a defect signal) of a defectwhich is a high frequency component and haze signal which is a lowfrequency component are included in outputs of the detectors 120 a to120 d.

In the scattered light detecting section 104, amplifiers 121 a to 121 dand A/D converters 122 a to 122 d are respectively connected to thedetectors 120 a to 120 d. Detection signals from the detectors 120 a to120 d are amplified through the amplifiers 121 a to 121 d, and digitizedthrough the A/D converters 122 a to 122 d.

The signal synthesizing section 105 synthesizes the digitized detectionsignals from the detectors 120 a to 120 d in accordance with adesignated calculation condition (program). The later-describedcalculation condition of the synthesized signal in the signalsynthesizing section 105 is not predetermined fixed condition, and thecalculation condition can appropriately designated and changed by anoperator using the input operating section 109. Data of the synthesizedsignal which is synthesized by the signal synthesizing section 105 isoutput to the storing section 110 and stored therein together with dataof detection signals of the detectors 120 a to 120 d which are bases ofthe synthesized signal. Examples of these data sets are positions (XYcoordinates) and sizes of individual detected defects. These data setsmay be output to an inspection apparatus using an electron microscope orother inspection apparatuses and producing apparatuses through anetwork.

The general control section 106 processes signals concerning display,input and output of information required for steps of operations(setting of inspection condition, display of results, analysis anddesignation of calculation equation), and control the entire apparatus.For example, the general control section 106 outputs a command signal tothe mechanical control section 107 based on an operation signal from theinput operating section 109 and a corresponding program stored in thestoring section 110, and changes the calculation condition of thesynthesized signal in the signal synthesizing section 105. Themechanical control section 107 receives the command signal from thegeneral control section 106 and controls driving mechanisms such as therotation driving section 115 and the slide driving section 116. Thegeneral control section 106 also outputs, to the storing section 110, asynthesized signal which is input through the signal synthesizingsection 105 and a detection signals from the detectors 120 a to 120 d,and allows the storing section 110 to store these signals, and producesa display signal to the information display section 108 based on thesesignals, and display an image on the information display section 108.

The input operating section 109 is for instructing input operation of asynthesizing condition of a detection signal by the signal synthesizingsection 105 and operation of each apparatus.

The information display section 108 displays a sample image (called“synthesized sample image”, hereinafter for convenience sake) structuredbased on a synthesized signal synthesized by the signal synthesizingsection 105 in accordance with a condition designated by the inputoperating section 109, a plurality of sample images (called “individualsample images”, hereinafter for convenience sake) corresponding toindividual detectors structured based on a detection signal from acorresponding detector, and detection data and a detection condition(recipe). For example, the information display section 108 displays aresult of inspection after the inspection is completed, and displays asynthesized sample images and an individual sample images on the samescreen at the time of analysis. The synthesized sample images and theindividual sample images may be displayed in a switching manner.

The storing section 110 stores, therein, programs required for variouscontrol and calculations, constants, inspection results (data ofsynthesized sample images and individual sample images), and asynthesizing condition which is set by the input operating section 109.Data of the individual sample image of each of the detectors 120 a to120 d is stored together with address information of the detectors.

As described above, the synthesis of a detection signal by the signalsynthesizing section 105 is executed in accordance with a conditionwhich is set by an operator using the input operating section 109. Thissetting can always be changed by inputting operation of the inputoperating section 109.

FIGS. 2 to 4 show several examples of the synthesizing condition of adetection signal. FIG. 2 shows one useful example to suppress a noise ina specific orientation, and to enhance a defect detection S/N. Based onthe fact that the detection signal has orientational properties, a noiselevel is optimized in accordance with a inspection purpose by making itpossible to freely set a constant which is to be multiplied by thedetection signal of the each detectors, because of differences in theorientations of the detectors from the illumination light spot.

In the example shown in FIG. 2, when synthesizing defect signals 1 and 2detected by the detectors 120 a and 120 b at the low angle (elevationangle 1), a signal obtained by multiplying the defect signal 1 by 1/n₁,and a signal obtained by multiplying the defect signal 2 by 1/n₂ areadded. At that time, 1/n₁ and 1/n₂ are arbitrary numeric values whichare input by an operator using the input operating section 109 whiletaking, into consideration, positions of the detectors 120 a and 120 bwith respect to the illumination light spot in accordance with theinspection purpose. Similarly, when synthesizing defect signals 3 and 4detected by the detectors 120 c and 120 d at the high angle (elevationangle 2), a signal obtained by multiplying the defect signal 3 by 1/n₃,and a signal obtained by multiplying the defect signal 4 by 1/n₄ areadded. Here also, 1/n₃ and 1/n₄ are arbitrary numeric values which areinput by an operator using the input operating section 109 while taking,into consideration, positions of the detectors 120 c and 120 d withrespect to the illumination light spot.

In the example shown in FIG. 3, when synthesizing the defect signals 1and 2 detected by the detectors 120 a and 120 b at the low angle(elevation angle 1), a signal obtained by dividing the defect signal 1by a haze signal 1 detected by the detector 120 a, and a signal obtainedby dividing the defect signal 2 by a haze signal 2 detected by thedetector 120 b are added. Similarly, when synthesizing defect signals 3and 4 detected by the detectors 120 c and 120 d at the high angle(elevation angle 2), a signal obtained by dividing the defect signal 3by a haze signal 3 detected by the detector 120 c, and a signal obtainedby dividing the defect signal 4 by a haze signal 4 detected by thedetector 120 d are added. In the case of this embodiment, it is possibleto easily change the synthesizing condition shown in FIG. 2 to thesynthesizing condition for enhancing S/N using the haze signals shown inFIG. 3 by means of the input operating section 109.

FIG. 4 shows one example for obtaining classification information of thedetection signals. In FIG. 4, when synthesizing the defect signals 1 to3 from the detectors at the elevation angle 1 located in a frontdirection of, in a side direction of and in a rear direction of theillumination light spot, the detection signals 1 to 3 are multiplied byarbitrary coefficients and added like the example shown in FIG. 2. Thissynthesizing condition is not limited, and may be replaced by thesynthesizing condition shown in FIG. 3.

At that time, a correlation between detection signals detected bydetectors at various positions generated by sizes of the signals andinspection purposes (flaw, foreign matter, COP and the like) is takenconditions, and a result obtained by such a condition may be obtained asclassification information (any attribute signal which can beidentified) of a defect. In the example shown in FIG. 4, sizes of thedefect signal 1 which is multiplied by 1/n₁ and the defect signal 2which is multiplied by 1/n₂ are compared with each other, and if thedefect signal 1 is greater than the defect signal 2, an attributeidentified by 0 (zero) is given to information such as a size and aposition of a detected defect and a detector address as theclassification information, and if the defect signal 1 is smaller thanthe defect signal 2, an attribute identified by 1 is given. That is,kinds of defects are identified by the attribute information (0 or 1)incidental to the detected defect information. In this example, a defectis classified by means of a ratio between scattered light (scatteredlight dispersed forward) detected by a detector disposed in the frontdirection of the illumination light spot and scattered light (scatteredlight dispersed sideward) detected by a detector disposed in the sidedirection of the illumination light spot.

By classifying a defect in this manner, each kind of defect afterclassification can have precise sensitive curve, and this also enhancethe detection precision of size of defect.

FIG. 5 shows one example of an analysis screen displayed on theinformation display section 108. As shown in FIG. 5, a display region230 of total eight individual maps 230 a to 230 h and a display region240 of an enlarged map 240 a on which selected one of the individualmaps 230 a to 230 h is displayed in an enlarged scale are disposed inthe analysis screen 200. In the example shown in FIG. 5, the scatteredlight detecting section 104 has total eight detectors comprisingdetectors L1 to L4 at low angle disposed in four orientations, anddetectors H1 to H4 at high angle disposed in four orientations.

The individual sample image is displayed on the individual map 230 a insuch a form that a defect detected by the detector L1 at correspondinglow angle is superposed on a wafer map. Similarly, individual sampleimages detected by corresponding detectors L2 to L4 and H1 to H4 aredisplayed on the individual maps 230 b to 230 h. The individual maps 230a to 230 h may be displayed at locations corresponding to the actuallayout of the detectors L1 to L4 and H1 to H4.

On the enlarged map 240 a, any one of the individual maps 230 a to 230 hselected by an inputting operation using the input operating section 109or a touching operation of the individual maps 230 a to 230 h. Ahistogram having a size of a defect displayed on the enlarged map 240 ais displayed in a lower range of the enlarged map 240 a in the analysisscreen 200.

With this, the enlarged map 240 a and the histogram can sequentially bechecked for each of the individual maps 230 a to 230 h, defectdistribution of each size can be checked, and a range difference in anoise level can be determined. If the individual maps 230 a to 230 h aredisplayed on the analysis screen 200 in the form of a list, dependencytendency of distribution of defect size toward the detector orientationcan also be checked.

FIG. 6 shows one example of a simulation screen displayed on theinformation display section 108. The simulation screen 201 shown in FIG.6 is a screen in which display is shifted by an analysis screen 200 by atouching operation of a display switching button (not shown) provided onthe analysis screen 200 or an operation using an input operating section109. The simulation screen 201 may be provided with the displayswitching button (not shown) to the analysis screen 200, and the displaymay be shifted to the analysis screen 200 by the touching operation ofthe display switching button or the operation using the input operatingsection 109.

A condition setting region 210 for setting a synthesizing condition(calculation equation) of a detection signal, and a simulation region220 where a synthesizing map (calculation result) 220 a by a synthesizedsignal based on the synthesizing condition set in the condition settingregion 210 are disposed in the simulation screen 201 in addition to thedisplay region 230 of the individual maps 230 a to 230 h. Thesynthesizing map 220 a may be displayed on the enlarged map 240 a of theanalysis screen 200.

The condition setting region 210 is provided with a display region 211of the synthesizing condition, and a synthesizing condition which is setby an inputting operation using the input operating section 109 or atouching operation of various operator buttons 212 a to 212 e and theindividual maps 230 a to 230 h provided in the condition setting region210 is displayed in the condition setting region 210. In the exampleshown in FIG. 6, a case where a detection signal of the detector L1 ismultiplied by a coefficient 0.5 (=½) and a result thereof is added tothe detection signal is shown in the display region 211 as asynthesizing condition of signals of the detectors L1 to L4 at lowangle. In this case, the inspection purpose and the orientations of thedetectors are taken into consideration, and an operator inputs asynthesizing condition for weakening a detection signal of the detectorL1 located in a specific orientation as compared with other detectors L2to L4.

In addition to operators such as “+ (addition)”, “− (subtraction)”, “×(multiplication)”, “÷ (division)” and “^ (exponentiation)” with respectto arbitrary two inputs and constant, operators of condition branch, atotal (Σ) of a plurality of values are appropriately combined, and oneof a plurality of calculation layers as shown in FIGS. 2 to 4 are set,and a synthesizing condition of a detection signal is set. When valuesobtained by multiplying detection signals of the detectors bycoefficients are summed up, it is conceived that slider switches (scrollbars) are provided near the individual maps 230 a to 230 h so thatcoefficients with respect to the detection signals can be changed byoperating the slider switches. In this embodiment, the setting of thesynthesizing condition of the detection signal can be changed veryeasily on the screen of the information display section 108 by the GUIoperation.

A synthesized sample image is displayed on the synthesizing map 220 a inaccordance with the display region 211 shown in FIG. 6 or a synthesizingcondition shown FIGS. 2 to 4 in such a form that detection signals ofthe detectors are synthesized by the signal synthesizing section 105 toobtain a synthesized signal, and a defect image produced based on thesample stage is superposed on a wafer map. If the synthesizing conditionof the detection signals of the detectors is changed by theabove-described operation, a synthesized sample image structured by asynthesized signal in accordance with a synthesizing condition afterchange is reflected to the synthesizing map 220 a, and a result ofdetection of the inspection apparatus by the change of the synthesizingcondition is always simulated by the simulation region 220.

An operator arbitrarily sets a synthesizing condition of a signal whileseeing detection signals of the detectors by the inspection purpose andthe individual map. With this, it is possible to customize theinspection apparatus and to optimize an inspection result in accordancewith the inspection purpose.

FIG. 7 shows one example of a data list display screen displayed on theinformation display section 108. A coordinate position (X, Y) on awafer, detection sizes by the detectors L1 to L4 and detection size bysynthesized signal under a set synthesizing condition are displayed onthe data list display screen 202 with respect to defects (Nos. 1, 2 . .. ) in a form of a list. Information from which distribution andtendency of data can visually be discriminated such as a histogram ofsize of a detected defect and a chart are also displayed in addition tothe list.

The data list display screen 202 can be switched to a previous analysisscreen 200 and the simulation screen 201 by operating the displayswitching button (object on the screen 202) (not shown) or operation bythe input operating section 109.

FIG. 8 is a flowchart showing setting procedure of a synthesizingcondition of a detection signal using the appearance inspectionapparatus having the above-described structure. When a synthesizingcondition of a detection signal is to be changed in the appearanceinspection apparatus of the embodiment, a wafer whose coordinates, sizeand kind of a defect are known to some extent in another inspectionapparatus is loaded onto a sample stage 101, and a defect inspection iscarried out under the current synthesizing condition (or resetsynthesizing condition) (step 301). If the input operating section 109instructs to start the inspection, illumination light from theillumination light source 103 is scanned on the rotating sample 100, andscattered light from the sample 100 is detected by each detector. Thedetection signal by each detector is synchronized with a position(coordinates) of the illumination light spot on the sample 100 by amotion signal of the sample stage 101 which instructs the mechanicalcontrol section 107, and a result of detection of each detector isstored in the storing section 110 together with defect information suchas coordinates, size, detector address and a synthesized signal.

In step 302, a predetermined operation is carried out on the inputoperating section 109 or the information display section 108, theinformation display section 108 is instructed to display the analysisscreen 200 of FIG. 5, and a result of the inspection is analyzed(sensitivity is checked for example). The general control section 106which receives an operation signal from the input operating section 109reads a detection signal and a synthesized signal of each detectorstored in the storing section 110, and a display signal produced basedon these information sets is output to the information display section108. With this, the analysis screen 200 is displayed on the informationdisplay section 108. The operator checks a result of detection by eachdetector under the current condition by the individual maps 230 a to 230h and the enlarged map 240 a, the current inspection result is comparedwith the known defect information, and it is analyzed whether theinspection result is excellent.

In step 303, a result of the analysis and the current signalsynthesizing condition meet the next inspection purpose (if the currentsensitivity is sufficient in the case of sensitive optimization), it isunnecessary to change the synthesizing condition and thus, thesynthesizing condition setting procedure is completed, and an inspectionstep of a wafer is started using the current synthesizing condition asit is. If the current signal synthesizing condition does not meet theinspection purpose (if the current sensitivity is insufficient in thecase of sensitive optimization), the procedure is proceeded tosynthesizing condition changing procedure in steps 304 and 305.

In step 304, the inspection purpose (kind of defect to be inspected), aposition of a detector (orientation, elevation angle), defect haze andthe like are taken into consideration, and the individual map, theenlarged map, the histogram and the like are checked on the analysisscreen 200.

In step 305, display of the information display section 108 is switchedto the simulation screen 201, and as results of evaluation and analysisin the analysis screen 200, a synthesizing condition meeting theinspection purpose are determined, and they are newly set in thecondition setting region 210. Results of change in the synthesizingcondition are sequentially reflected on the synthesizing map 220 a andthe individual maps 230 a to 230 h. In step 305, a synthesizingcondition after change is output to the storing section 110 and storedtherein through the general control section 106. The stored newsynthesizing condition is read by the general control section 106together with detection signals of the detectors, display data of thesynthesized sample image is produced by the general control section 106based on the new synthesizing condition, and the display data is outputto the information display section 108. The validity of the synthesizingcondition is evaluated by a simulation image displayed on thesynthesizing map 220 a, and if it is determined that the synthesizingcondition is valid, the synthesizing condition is once determined.

In next step 306, a defect inspection of the same wafer is again carriedout under the newly set synthesizing condition, and a result thereof isanalyzed in step 307 as in the same manner as that in step 302. In step308, in the same manner as that in step 303, if a signal synthesizingcondition after change meets the inspection purpose (if the currentsensitivity is sufficient in the case of sensitive optimization), it isunnecessary to change the synthesizing condition thereafter and thus,the inspection synthesizing condition setting procedure is completed,and an inspection step of a wafer is started using the currentsynthesizing condition as it is. If the signal synthesizing conditionafter change does not yet meet the inspection purpose (if the currentsensitivity is insufficient in the case of sensitive optimization), theprocedure is returned to step 304, and attempt is made to change thesynthesizing condition again. The change in synthesizing condition and atrial inspection under the synthesizing condition after change arerepeated and if an excellent inspection result is obtained, theprocedure in FIG. 8 is completed.

According to this embodiment, the following effects can be obtained.When a defect such as a COP, a flaw, a foreign matter (particle) or thelike on a wafer is to be inspected, in an appearance inspectionapparatus having a plurality of detectors (multi-sensors) a synthesizingcondition of a detection signal of each detector is set as a parametersuitable for a kind of the defect to be detected. Thus, when theinspection purpose is to be changed, it is necessary to change theparameter to optimize the sensitivity in accordance with a kind of thedefect of the purpose. In this case, to change a parameter, much laborand time are required for a series of operations including evaluation ofan inspection result on off-line operation, analysis, preparation ofsoftware and install of the prepared software in some cases.

According to the embodiment, a result of inspection of a defect of awafer can be checked in the information display section 108 and afterthat, it is possible, on the appearance inspection apparatus, toevaluate and analyze the inspection result, to change a signalsynthesizing condition by the input operating section 109, to simulate asynthesizing map after change, and to check a result of an inspectionafter the condition is changed. A difference in detectioncharacteristics of detection signals obtained by a plurality ofdetectors is analyzed on the apparatus, and it is possible to flexiblyand swiftly satisfy various inspection purposes with minimum laborwithout changing a circuit and software. Since multi-sensors aremounted, it is possible to discriminate differences of detection signalsin accordance with orientational properties of scattered light dependingon kinds of defects and with this, such a large merit can be obtained.

It is possible to arbitrarily and easily change a synthesizing conditionof a detection signal. Thus, trial inspections can be repeated undervarious synthesizing conditions, and if a result of detection and atendency thereof (orientation of detection signal, dependency onelevation angle and the like) are analyzed, it is possible to expectapplication of defects to specification of parameters for inspection andclassification which could not easily be found in the appearanceinspection apparatus of this kind.

1. An appearance inspection apparatus comprising: a sample stage forsupporting a sample, an illumination light source for irradiating thesample on the sample stage with illumination light, a plurality ofdetectors which are disposed at different positions from each other withrespect to an illumination light spot of the illumination light source,and which detect scattered light generated from a surface of the samplewhen illumination light is emitted from the illumination light source, asignal synthesizing section which synthesizes detection signals from theplurality of detectors in accordance with a set condition, a conditionsetting section for setting a synthesizing condition of the detectionsignal by the signal synthesizing section, and a display section fordisplaying a synthesized sample image structured based on a synthesizedsignal which is synthesized by the signal synthesizing section inaccordance with a condition set by the condition setting section.
 2. Aninspection apparatus comprising: a moving system that moves a substrate;an illumination system that irradiates said substrate with light; adetection system that detects light from said substrate; and aprocessing unit; wherein said detection system comprises a firstdetection unit and a second detection unit; wherein said first detectionunit and said second detection unit are arranged at different positions;wherein said detection system outputs a first detection signal of saidfirst detection unit and a second detection signal of said seconddetection unit independently each other; wherein the processing unitcombines said first detection signal and said second detection signal;wherein a condition of combination of said first and second detectionsignals is changeable flexibly; wherein said processing unit processesat least one of said first detection signal and said second detectionsignal; and wherein said first detection signal includes a first defectsignal and a first haze signal, and said processing unit multiplies saidfirst defect signal by an inverse of said first haze signal.
 3. Aninspection apparatus comprising: a moving system that moves a substrate;an illumination system that irradiates said substrate with light; adetection system that detects light from said substrate; and aprocessing unit; wherein said detection system comprises a firstdetection unit and a second detection unit; wherein said first detectionunit and said second detection unit are arranged at different positions;wherein said detection system outputs a first detection signal of saidfirst detection unit and a second detection signal of said seconddetection unit independently each other; wherein the processing unitcombines said first detection signal and said second detection signal;wherein a condition of combination of said first and second detectionsignals is changeable flexibly; wherein said processing unit processesat least one of said first detection signal and said second detectionsignal; and wherein said second detection signal includes a seconddefect signal and a second haze signal, and said processing unitmultiplies said second defect signal by an inverse of said second hazesignal.
 4. An inspection apparatus comprising: a moving system thatmoves a substrate; an illumination system that irradiates said substratewith light; a detection system that detects light from said substrate;and a display system; wherein said detection system comprises a firstdetection unit and a second detection unit; wherein said first detectionunit and said second detection unit are arranged at different positions;wherein said detection system outputs a first detection signal of saidfirst detection unit and a second detection signal of said seconddetection unit independently of each other; wherein the display systemdisplays said first detection signal and said second detection signalindividually; wherein a processing system combines said first detectionsignal and said second detection signal; wherein a condition ofcombination of said first and second detection signals is changeableflexibly; and wherein said first detection signal includes a firstdefect signal and a first haze signal, and said processing systemmultiplies said first defect signal by an inverse of said first hazesignal.
 5. An inspection apparatus comprising: a moving system thatmoves a substrate; an illumination system that irradiates said substratewith light; a detection system that detects light from said substrate;and a display system; wherein said detection system comprises a firstdetection unit and a second detection unit; wherein said first detectionunit and said second detection unit are arranged at different positions;wherein said detection system outputs a first detection signal of saidfirst detection unit and a second detection signal of said seconddetection unit independently of each other; wherein the display systemdisplays said first detection signal and said second detection signalindividually; wherein a processing system combines said first detectionsignal and said second detection signal, wherein a condition ofcombination of said first and second detection signals is changeableflexibly; and wherein said second detection signal includes a seconddefect signal and a second haze signal, and wherein said processingsystem multiplies said second defect signal by an inverse of said secondhaze signal.
 6. An inspection process comprising: moving a substratewith a moving system; irradiating said substrate with light by way of anillumination system; detecting light from said substrate with adetection system comprising a first detection unit and a seconddetection unit arranged at different positions; outputting from saiddetection system a first detection signal of said first detection unitand a second detection signal of said second detection unitindependently each other; and combining said first detection signal andsaid second detection signal in a processing unit such that a conditionof combination of said first and second detection signals is changeableflexibly; wherein said processing unit processes at least one of saidfirst detection signal and said second detection signal; and whereinsaid first detection signal includes a first defect signal and a firsthaze signal, and said first defect signal is multiplied by an inverse ofsaid first haze signal.
 7. An inspection process comprising: moving asubstrate with a moving system; irradiating said substrate with light byway of an illumination system; detecting light from said substrate witha detection system comprising a first detection unit and a seconddetection unit arranged at different positions; outputting from saiddetection system a first detection signal of said first detection unitand a second detection signal of said second detection unitindependently each other; and combining said first detection signal andsaid second detection signal in a processing unit such that a conditionof combination of said first and second detection signals is changeableflexibly; wherein said processing unit processes at least one of saidfirst detection signal and said second detection signal; and whereinsaid second detection signal includes a second defect signal and asecond haze signal, and said second defect signal is multiplied by aninverse of said second haze signal.
 8. An inspection process comprising:moving a substrate with a moving system; irradiating said substrate withlight by way of an illumination system; detecting light from saidsubstrate with a detection system comprising a first detection unit anda second detection unit arranged at different positions; outputting fromsaid detection system a first detection signal of said first detectionunit and a second detection signal of said second detection unitindependently of each other; displaying said first detection signal andsaid second detection signal individually; and combining said first andsecond detection signals with a processing system such that a conditionof combination of said first and second detection signals is changeableflexibly; wherein said first detection signal includes a first defectsignal and a first haze signal, and said processing system multipliessaid first defect signal by an inverse of said first haze signal.
 9. Aninspection process comprising: moving a substrate with a moving system;irradiating said substrate with light by way of an illumination system;detecting light from said substrate with a detection system comprising afirst detection unit and a second detection unit arranged at differentpositions; outputting from said detection system a first detectionsignal of said first detection unit and a second detection signal ofsaid second detection unit independently of each other; displaying saidfirst detection signal and said second detection signal individually;and combining said first and second detection signals with a processingsystem such that a condition of combination of said first and seconddetection signals is changeable flexibly; wherein said second detectionsignal includes a second defect signal and a second haze signal, andwherein said processing system multiplies said second defect signal byan inverse of said second haze signal.
 10. An inspection apparatuscomprising: an illumination system that illuminates a substrate withlight; a detection system that detects light from said substrate, saiddetection system including a first detection unit that outputs a firstsignal and a second detection unit that outputs a second signal, saidfirst and second detection units being arranged at different positions;a processing system that includes a layer for processing at least one ofsaid first and second signals using a defect signal and a haze signal;and a setting system for setting a process condition in said layer;wherein said process condition is changeable flexibly.
 11. Theinspection apparatus according to claim 10, wherein said processingsystem includes a first layer for outputting a first processed signal,acquired by processing said first signal, and a second processed signal,acquired by processing said second signal.
 12. The inspection apparatusaccording to claim 11, wherein said processing system further includes asecond layer for processing said first and second processed signalstogether.
 13. The inspection apparatus according to claim 11, whereinsaid processing system further acquires a combined image of saidsubstrate using said first and second processed signals.
 14. Theinspection apparatus according to claim 10, wherein at least one of saidfirst and second signals includes a simulation signal.
 15. Theinspection apparatus according to claim 10, wherein said processingsystem includes a plurality of layers connected with each other, andprocess conditions of said layers are different from each other.
 16. Theinspection apparatus according to claim 10, wherein said setting systemincludes a display unit, said display unit displays a plurality of iconsfor setting process conditions in said layer, and combinations of saidicons are changeable flexibly.
 17. The inspection apparatus according toclaim 10, wherein said setting system includes a display unit, saiddisplay unit displays a plurality of icons for setting processconditions in said layer, and types of said icons are changeableflexibly.
 18. The inspection apparatus according to claim 10, whereinsaid processing system includes a classification layer for classifyingdefect type after processing at least one of said first and secondsignals using a defect signal and a haze signal.
 19. An inspectionprocess comprising: illuminating a substrate with light from anillumination system; detecting light from said substrate with adetection system having a first detection unit that outputs a firstsignal and a second detection unit that outputs a second signal, saidfirst and second detection units being arranged at different positions;processing at least one of said first and second signals with a layer ofa processing system using a defect signal and a haze signal; and settinga flexibly changeable process condition in said layer with a settingsystem.
 20. The inspection process according to claim 19, wherein saidprocessing system includes a first layer for outputting a firstprocessed signal, acquired by processing said first signal, and a secondprocessed signal, acquired by processing said second signal.
 21. Theinspection process according to claim 20, wherein said processing systemfurther includes a second layer for processing said first and secondprocessed signals together.
 22. The inspection process according toclaim 20, wherein said processing system further acquires a combinedimage of said substrate using said first and second processed signals.23. The inspection process according to claim 19, wherein at least oneof said first and second signals includes a simulation signal.
 24. Theinspection process according to claim 19, wherein said processing systemincludes a plurality of layers connected with each other, and processconditions of said layers are different from each other.
 25. Theinspection process according to claim 19, wherein said setting systemincludes a display unit, said display unit displays a plurality of iconsfor setting process conditions in said layer, and combinations of saidicons are changeable flexibly.
 26. The inspection process according toclaim 19, wherein said setting system includes a display unit, saiddisplay unit displays a plurality of icons for setting processconditions in said layer, and types of said icons are changeableflexibly.
 27. The inspection process according to claim 19, wherein saidprocessing system includes a classification layer for classifying defecttype after processing at least one of said first and second signalsusing a defect signal and a haze signal.